What is Koji? (麹)

Koji is the product's name that breeds fungi called “Aspergillus oryzae” (麹菌: Koji-kin) with either steamed rice, soybeans or barley.

It’s an essential ingredient in making miso, sake, and mirin.

Shio Koji is a useful condiment made from rice koji, salt and water.

Health benefits of Shio Koji

Grilled Shio-koji pork with kimchi and lettuce.
Grilled Shio-koji pork with kimchi and lettuce.

I enjoy using Shio Koji because it’s healthy and an excellent salt alternative. It makes meat and fish tender and juicy thanks to its enzyme that turns proteins into amino acids, increasing the umami flavour and helping you digest it.
This enzyme also creates oligo sugar in your stomach, and these are fantastic food for probiotics. When you consume Shio Koji regularly, probiotics in your gut will increase. Having more probiotics than negative bacteria in your stomach is a general sign of healthiness.

If your stomach is already in good condition, it helps strengthen your immune system, regulate bowel movements, and relieve stress.

Homemade Shio Koji (塩麹, 塩糀)


300g Rice Koji

100g Sea salt

450ml water (I used filtered water)


A bowl

A spoon

A sterilised glass jar with a lid


  1. Place rice koji and sea salt in a clean bowl and mix until combined well.
  1. Add the water and mix well.
  1. Put into the glass jar and put the lid on. Do not close it during the fermentation process to remove the excess gas.
  2. Leave it at room temperature for 5 to 7 days (~20°C). Mix it with a clean spoon every day. Make sure the surface of the Shio koji is covered in water. Add some water when necessary.
  1. Once it's ready, close the lid, keep it in the fridge, and use it within three months.

If you are unsure how much you can use to marinate, try 10g of Shio Koji to marinate 100g of the ingredients to see if you like it.

How I use the Shio koji

Marinate meat and fish

As mentioned in the health benefits section, marinating meat or fish makes them tender and juicy. You just need to be aware that it’s easy to get burnt and not marinate for a long time since it gets salty. Generally, I marinate them overnight.

Make pickles

The best way of consuming Shio Koji is raw. When it reaches more than 60°C, the enzyme loses its power. Simply add to chopped cucumber and marinate to make some pickles. It would be a great side dish for summer. Adding some sesame oil is great too.


Using Shio Koji in a dressing is a great way to consume it raw. Mix Shio Koji, oil, and vinegar and pour over your favourite salad. You can customise the oil and vinegar to find your favourite combinations.

Closing words

Grilled Shio-koji salmon.
Grilled Shio-koji salmon.

What did you think of Shio Koji? Was it something new for you, or did you already know about it and use it? Either way, I highly recommend trying!
I will keep trying different fermented food, make them at home, and share their great benefits to our daily lives.
Please share your thoughts on Instagram, Pinterest, and Facebook. It may also help other people discover this great condiment! If you're not already,  subscribe to our email list so you don’t miss our updates.